Dishwasher apparatus



Jan. 14, 1969 w. G. PEYER ET AL 3,421,704

DISHWASHER APPARATUS Sheet Filed April 4,1966

fhza amk ATTORNEY Jan. 14, 1969 w. G. PEYER ET AL 3,421,704

DISHWASHER APPARATUS Sheet Filed April 4, 1966 United States Patent 4 Claims ABSTRACT OF THE DISCLOSURE A dishwasher pump means including an impeller having a first portion for pumping water to the Washing chamber and a unitarily integral second portion for pumping water to the drain, the second portion of the impeller being arranged to provide a higher fluid pressure than that produced by the first portion whereby improved discharging of the washing liquid is obtained with a minimum of recirculation of the washing liquid during the drain cycle.

This invention relates to dishwasher apparatus and in particular to pump means for use therein.

In conventional dishwasher apparatus, pump means are provided for recirculating washing liquid to the dishwashing chamber. Further, pump means are provided for pumping the washing liquid to a suitable drain upon completion of the dishwashing cycle. It has heretofore been conventional to provide a reversing motor for operating the pump means so as to provide selectively the different liquid pumping operations. Conventionally, either separate pumps or pumps connected in tandem to be driven by the reversing motor have been employed for this purpose. Such conventional apparatus has the serious disadvantage of relatively high cost, such as attendant the use of such multiplicity of equipment. The present invention permits the use of a unidirectional motor with a single pump effectively eliminating the above discussed disadvantages of the conventional apparatus.

Thus, a principal feature of the present invention is the provision of a new and improved pump means for use with a dishwasher apparatus and the like.

Another feature of the invention is the provision of such improved pump means utilizing a single impeller in a novel manner to provide selective recirculation and drain operations of the dishwasher.

A further feature of the invention is the provision of such a pump means having a novel stepped impeller providing improved recirculation and drain functioning of the apparatus.

Still another feature of the invention is the provision of such a pump means including means for cooperation with a portion of the impeller for comminuting material in the washing liquid during a drain operation.

A yet further feature of the invention is the provision of such a pump means wherein the passages for conducting the washing liquid from the pumping chamber open radially thereinto for improved pumping efficiency.

A further feature of the invention is the provision of such a pumping means wherein the passage means for conducting washing liquid from the pumping chamber to the dishwashing chamber is provided with a converter for converting the flow of dishwashing liquid from a radial direction upon leaving the pumping chamber to an axial direction for facilitated delivery to the dishwashing chamber.

Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying. drawing wherein:

FIGURE 1 is a fragmentary front elevation of a dish- 3,421,704 Patented Jan. 14, 1969 washer apparatus provided with a pumping means embodying the invention, with portions broken away to facilitate the illustration thereof;

FIGURE 2 is a fragmentary enlarged diametric section of the pumping means;

FIGURE 3 is a fragmentary transverse section taken substantially along the line 33 of FIGURE 2;

FIGURE 4 is a reduced fragmentary transverse section taken substantially along the line 4-4 of FIGURE 2; and

FIGURE 5 is a fragmentary enlarged transverse section taken substantially along the line 55 of FIGURE 2.

In the exemplary embodiment of the invention as disclosed in the drawing, a dishwasher apparatus generally designated 10 is shown to include a tub 11 defining a dishwashing chamber 12 and having a bottom wall 13 carrying a pump means generally designated 14 driven by a suitable unidirectional electric motor 15. The motor 15 further rotatably drives a spray arm 16 carried on a suitable hub 17 for delivering washing liquid into the washing chamber 12 as for washing dishes and the like (not shown) suitably disposed therein. A drain 18 is provided with a suitable electric solenoid valve 19 for selectively opening and closing the drain.

As indicated briefly above, the improved pumping means is arranged for selective delivery of the washing liquid to the washing chamber 12 or to the drain 18. More specifically, as best seen in FIGURE 2, pumping means 14 includes an impeller '20 provided with a plurality of unitary, integral stepped blades 21 each having a first, upper portion 22 at a first radial distance from the axis 23 of the shaft 24 of motor 15, and a second, lower portion 25 disposed at a second radial distance from axis 23 greater than the radial distance of portion 22. As best seen in FIGURE 5, the first portion 22 of the blades is arcuate in horizontal cross-section to define a centrifugal pumping means. As shown in FIGURE 2, the axial extent of blade portion 22 is substantially greater than the axial extent of blade portion 25.

The impeller 20 is disposed within a pumping chamber 26 defined in part by an upper housing member 27 defining a plurality of first passage means comprising hollow leg portions 28 provided at their respective lower ends with an opening 29 and terminating at their upper ends in a common discharge chamber 30 communicating internally with the hub 17 of the spray arm for conducting washing liquid upwardly thereto. The washing liquid centrifugally pumped by the blade portions 22 is redirected from a centrifugal flow direction to an axial flow direction by a converter member 31 defining a curved inlet 32 opening at its upper end to the opening 29 of the housing 27. As shown in FIGURE 2, the housing 27 may be provided with a lower annular flange 33, and the converter 31 may be provided with a corresponding, upper annular flange 34 disposed subjacent flange 33. The flanges 33 and 34 are carried on a pump liner 35, and the assembly thereof is secured to the bottom wall 13 of the tub 11 by suitable means such as nut and bolt means 36. As shown in FIGURE 2, the liner includes a bottom portion 37 defining the lower end of the pumping chamber 26 and having an axial, upwardly opening well portion 38 receiving a seal 39 for sealing the shaft 24 to the liner. The liner 35 further defines a second passage means comprising a radially outwardly extending tubular outlet 40 which as shown in FIGURE 1 is connected to the drain 18.

Washing liquid in tub 11 is conducted downwardly therefrom through a conducting means comprising a filter screen 41 carried on and extending between the housing 27 and the bottom wall 13 of the tub, and thence through the openings 42 between the respective legs 28 of the housing 27 into the pumping chamber 26.

During a washing cycle, the washing liquid is recireulated by the pump 14 as a result of the closing of the valve 19 which thereby prevents delivery of washing liquid through the passage 44 defined by the outlet 40. The blades 21 centrifugally pump the washing liquid into the inlet passages 32 of the converter 31 which redirects them from a flow transaxially of axis 23 to an upward axially directed flow through the openings 29 of the housiug 27 and thence upwardly through the hollow legs 28 to the spray arm 16. When, however, the valve 19 is opened by suitable electrical operation, the washing liquid is pumped by the blade portions 25 through the outlet passage 44 to the drain 18. As the lower blade portion 25 is disposed radially outwardly of the upper blade portion 22, a greater pressure is developed by the blade portion 25, thereby quickly discharging the washing liquid through the outlet passage 44 with a minimum of recirculation of the washing liquid being effected by the upper blade portions 22.

Further, during the drain operation, the blade portions 25 cooperate with the lower surface 43 of the converter 31 to comminute materials carried in the Wash water before delivering them to the outlet passage 44. Upon completion of the drain operation, the valve 19 may be closed whereupon further pumping of washing liquid subsequently delivered to the tub 11 may be efiected by the upper portion 22 of the blades 21 for recirculating the wash 'water as during a subsequent wash cycle.

Thus, pump 14 efiects an improved selective delivery of the washing liquid to the spray arm for recirculation in washing chamber 12 or to the outlet passage 44 for delivery to the drain by means of the centrifugal pumping blades 21 and 25 directing the washing liquid transaxially to the recirculation inlet passage 32 and the drain outlet passage 44, respectively, with valve 19 providing selection of the recirculation or drain cycle as desired. While the blades 21 may have similar radial dispositions of each of the portions 22 and 25 thereof by providing the blade portion 25 outwardly of the radial disposition of blade portion 22 as shown in the illustrated embodiment, an improved expedited draining operation may be effected as a result of the increased pressure effected thereby. Thus, an improved selective recirculation and drain cycle may be obtained in dishwasher apparatus with the unidirectional motor and with the single impeller structure 20, whereby pump means 14 is extremely simple and inexpensive while yet providing the highly desirable features discussed above.

While we have shown and described one embodiment of our invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as defined in the appended claims.

The embodiment of the invention in which an exclusive property or privilege is claimed is defined as follows;

1. 'In a dishwasher having a washing chamber and a drain, apparatus comprising:

a pump having a pumping chamber and an impeller in said pumping chamber;

means for rotating said impeller in said pumping chamber about a central axis, said impeller having a first portion disposed at a first radial distance fromsaid axis and a second portion unitarily integral with said first portion and disposed at a second radial distance and at a difierent axial position relative to said first portion;

means for conducting washing liquid from said Washing chamber to said pumping chamber;

means defining a first passage for conducting washing liquid pumped by said first portion of the impeller from said pumping chamber to said washing chamber;

means defining a second passage for conducting washing liquid pumped by said second portion of the impeller from said pumping chamber to said drain, whereby the fluid pressure in said drain is greater than that in said first passage; and

means for selectively closing said drain.

2. The dishwasher apparatus of claim 1 wherein said first portion of the impeller has an axial dimension substantially greater than said second portion of the impeller.

3. The dishwasher apparatus of claim 1 wherein means are provided for cooperation with said second portion of the impeller for comminuting material in said washing chamber pumped by said second portion to said drain.

4. The dishwasher apparatus of claim 1 wherein said first passage opens into said pumping chamber trans versely to said axis, and said first passage means includes a converter member for smoothly converting flow of washing liquid thereinto into axial flow.

References Cited UNITED STATES PATENTS 2,050,104 8/ 1936 Lauchenauer 103-l 11 3,079,094 2/1963 Brezosky et al. 24146 3,096,718 7/1963 Anderson 103111 3,323,529 6/1967 Geiger et a1 134-186 X FOREIGN PATENTS 30,009 10/1910 Great Britain. 610,726 3/1935 Germany.

ANDREW R. JUHASZ, Primary Examiner.

FRANK T. YOST, Assistant Examiner.

US. Cl. X.R. 

